A new rapid direct immunofluorescence assay, the SimulFluor direct fluorescent-antibody (DFA) assay, which can simultaneously detect herpes simplex virus types 1 and 2 (HSV-1 and -2) and varicella-zoster virus (VZV), was evaluated in comparison with our current standard procedures of (i) shell vial direct immunoperoxidase (shell vial IP) staining and cell culture for detection of HSV and (ii) cytospin DFA staining for VZV detection. A total of 517 vesicular, oral, genital, and skin lesion specimens were tested by all three procedures. For HSV detection, the SimulFluor DFA assay had an overall sensitivity, specificity, positive predictive value, and negative predictive value of 80.0, 98.3, 92.3, and 95.1%, respectively, when compared to culture. Shell vial IP staining had a sensitivity, specificity, positive predictive value, and negative predictive value of 87.6, 100, 100, and 96.9%, respectively, when compared with cell culture. The SimulFluor DFA assay, however, offers same-day, 1.5-hours results versus a 1-to 2-day wait for shell vial IP staining results and a 1-to 6-day wait for culture results for HSV. For VZV detection SimulFluor DFA staining detected 27 positive specimens as compared to 31 by our standard cytospin DFA technique-a correlation of 87.1%. A positive SimulFluor reaction for VZV is indicated by yellow-gold fluorescence compared to the bright apple-green fluorescence observed by cytospin DFA staining. There is no difference in turnaround time between the two assays. The SimulFluor DFA assay is a rapid immunofluorescence assay that can detect 80% of the HSV-positive specimens and 87% of the VZV-positive specimens with a 1.5-h turnaround time.Herpes simplex virus (HSV) and varicella-zoster virus (VZV) cause skin lesions in adults and children and may cause severe systemic disease in immunosuppressed hosts and neonates. HSV types 1 and 2 (HSV-1 and -2) can cause vesicular and ulcerative lesions on the genital area as well as oropharyngeal infection. Genital herpes infection is a public health concern, as the infection can be transmitted between sexual partners. Seroprevalence studies of herpes type-specific antibodies have shown an increase of over 30% in the prevalence of HSV-2 infections over the past two decades, with a nationwide incidence of more than 20% of those infected who are 12 years of age and older having detectable antibody to HSV-2 (2). HSV-1 is increasingly recognized as a cause of genital infection, especially in female patients. In the United Kingdom, the annual incidence of HSV-1 genital infection nearly tripled over a 7-period with an incidence of 79% found in one study (8). Most patients with genital herpes infection do not have symptoms and thus are not aware that they can infect their sex partners. Another concern with genital herpes is neonatal herpes. Pregnant women who acquire primary genital herpes shortly before labor are the ones most likely to infect the newborn (1).Herpes zoster virus is a common childhood disease and is also a serious infection in the elderly and imm...